xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

vfs: add faccessat2 syscall

Browse Source 
POSIX defines faccessat() as having a fourth "flags" argument, while the
linux syscall doesn't have it.  Glibc tries to emulate AT_EACCESS and
AT_SYMLINK_NOFOLLOW, but AT_EACCESS emulation is broken.

Add a new faccessat(2) syscall with the added flags argument and implement
both flags.

The value of AT_EACCESS is defined in glibc headers to be the same as
AT_REMOVEDIR.  Use this value for the kernel interface as well, together
with the explanatory comment.

Also add AT_EMPTY_PATH support, which is not documented by POSIX, but can
be useful and is trivial to implement.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This commit is contained in:
Miklos Szeredi
2020-05-14 16:44:25 +02:00
parent 55923e4d7d
commit c8ffd8bcdd
23 changed files with 62 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
include/linux/syscalls.h
View File

@@ -428,6 +428,8 @@ asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length);
#endif
asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len);
asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode);
asmlinkage long sys_faccessat2(int dfd, const char __user *filename, int mode,
int flags);
asmlinkage long sys_chdir(const char __user *filename);
asmlinkage long sys_fchdir(unsigned int fd);
asmlinkage long sys_chroot(const char __user *filename);
@@ -1333,11 +1335,11 @@ static inline int ksys_chmod(const char __user *filename, umode_t mode)
return do_fchmodat(AT_FDCWD, filename, mode);
}
extern long do_faccessat(int dfd, const char __user *filename, int mode);
long do_faccessat(int dfd, const char __user *filename, int mode, int flags);
static inline long ksys_access(const char __user *filename, int mode)
{
return do_faccessat(AT_FDCWD, filename, mode);
return do_faccessat(AT_FDCWD, filename, mode, 0);
}
extern int do_fchownat(int dfd, const char __user *filename, uid_t user,